code: def df_stock():
      np.random.seed(42)
      df_stock = pd.DataFrame(
          {
              "Google": np.random.randn(1000) + 0.2,
              "Apple": np.random.randn(1000) + 0.17,
          },
          index=pd.date_range("1/1/2000", periods=1000),
      )
      df_stock.index.name = "Date"
      df_stock = df_stock.cumsum()
      df_stock = df_stock + 50
  
      return df_stock
  
imports: import os
  import numpy
  import pandas
  import pytest
  import pandas_bokeh
label_desc: Use image node_id 1 for calling a global function with example usage: df_stock() and returns: df_stock